present invention refers to knobs for gas valves, and more particularly, to a safety knob for domestic use gas apparatuses, which prevents the user from inadvertently opening the gas tap and prevents that it be operated by children.
There are already available in the market domestic gas valves, which have a mechanism of coupling-uncoupling between a stem of the valve and a closing element. The latter can have the shape of a cone, a cylinder or a disc. In order to be able to operate the gas valve, it is necessary that the user push a knob to couple the stem for the opening and closing the elements of the valve. During this operation, the force of pushing on the knob must be sustained, and the knob simultaneously turned. (normally towards the left) so that the valve will open, thus permitting the regular flow of gas towards the burner.
However, one of the two problems of the assembly of the knobbed-gas valves is that they accidentally sometimes are operated by the user or mainly by children, thus causing the gas to escape through the burners and putting the home or building safety of the user where the apparatus is installed at risk.
There are already some safety devices available in the market for blocking children""s access to range knobs, for example, the U.S. Pat. No. 4300525 issued to Jesus Delgado and George Spector describes a safe knob assembly for a kitchen gas stove burner, comprising in combination, a knob integral with shank having a square central opening slidably fitted on a square end of a stem of a gas valve along a gas line of a stove, a cam-faced spur on a side of said shank, and a stationary stop mounted separately adjacent said spur in combination with means for axially moving said shank in response to rotation in one direction of said shank and wherein rotation in opposite direction is restricted by engagement of said spur and stop. However, the operation of the knob can be operated by children.
Another form of protecting gas range knobs from children is illustrated in the U.S. Pat. No. 4,527,540 issued to Kathryn A. Ryan, which describes a safety shield for isolating a heated appliance, such as a stove or an oven, from the reach of children includes a flexible sheet of material having securing portions along opposite vertical edges for securing the sheet adjacent the sides of the front face of the appliance and an arched shielding portion extending horizontally between the securing portions and spanning the front face of the appliance, the arched shielding portion being bowed outwardly away from the front face of the appliance to shield the appliance from the reach of children. However, the safety shield needs to be removed by the user in order to gain access to the gas knobs.
There are other designs such as guards that only cover the knobs, which are manufactured out of transparent, temperature resistant material.
In accordance with the above, the present invention refers to a safety knob for domestic gas apparatuses, which prevents or deters children from operating the valve.
It is therefore a first objective of the present invention to provide a safety knob for domestic gas apparatuses, which is difficult for children to operate.
It is another objective of the present invention to provide a safety knob for domestic gas apparatuses, which does not need additional elements to cover the ranges that alter their appearance or functionality.
An additional objective of the present invention is to provide a safety knob for domestic gas apparatuses, which can be used with any type of conventional safety valves.